Advice on avoiding foot pain after running

Before I explain my problem, I just wanted to let everyone know I am seeking a doctor's opinion, but unfortunately they can't take me as a new patient until late August. That's a long time to be wandering around potentially hurting myself, so I thought I'd see if anyone has any advice on how to get by from now until then.

I am currently 306lbs. I started at 330 in December. I've been running and strength training and completed my first 5k in April. Considering my weight, my aches and pains were getting better, not worse. My knees had never felt so good as they did in April.

Then at the beginning of June I was running on the treadmill. I got off and felt an intense pain in the bottom of my right foot (like a stabbing up through the bottom). I wear running shoes that were fitted for me at a pro running store, so I don't think that had anything to do with it. I could barely walk out of the gym and for the next couple of days walking from the couch to the kitchen was an ordeal of hobbling and limping. I stubbornly decided not to go see a doctor at the time, figuring it would heal if I took some ibuprofen, iced it, and rested for a while. I didn't go back to the gym for 4 weeks while it slowly got better until there was hardly any pain at all. Then I went back to the gym in early July.

Now I can walk on the foot fine, sometimes it aches when I take my first couple of steps, but the pain recedes quickly. I can run for about .3/4 of a mile before the pain comes back sharp and intolerable. I decided last week enough was enough and finally made a call to see someone.

The pain is in my right foot, middle of the foot, along the outer edge on the bottom. The pain is mostly an ache, but can also feel like a stabbing pain. Sometimes when I first stand up I have to ease my weight onto it in order to avoid instant pain, and usually after the first few steps the pain lessons. I wear Brooks Dyad running shoes, and have since gotten a new pair of the new version that came out a few weeks ago. Aside from ice, I don't do anything special when I come home from the gym.

Does anyone have any advice on if there's any way to prep my foot before working out, or afterwards? Have you experienced this kind of pain and what did you discover when you went to see the doctor? I don't know what to even expect. I'm honestly scared of finding out I'm going to need surgery and will be forced off it for several months. I've come so far in my weight loss I don't want to go backwards. I think that's why I've put off going in to see him in the first place. (I know it sounds silly - I should want to get better even if it means stopping my progress for a while, but it can still feel scary.)

Thanks for anything you can tell me :-)